The present invention relates to the field of inert practice mines, and, more particularly, to environmentally safe, degradable mines.
Practice mines are inert mines that mimic tactical mines in their shape, weight, launch and flight characteristics. Practice mines are very important to training personnel in proper procedures and responses when using a scatterable mine system. However, in order to protect the environment, practice mines from scatterable mine systems currently require recovery and cleaning after use. One type of practice mine launching system is described in U.S. patent application Ser. No. 09/592,481, to Klukas et al., entitled Reusable Training Dispenser, having a filing date of Jun. 9, 2000 and assigned to the assignee of this patent application. U.S. patent application Ser. No. 09/592,481 is incorporated by reference herein. The Reusable Training Dispenser presents a metal dummy mine that matches the weight, launch and flight characteristics of a tactical mine almost exactly.
Unfortunately, procedures for recovery and cleaning of existing metallic practice mines are time consuming, inefficient, and expensive. The elimination of this low value-added step of recovery and cleaning would allow more efficient and cost-effective training procedures. Thus, the existence of a practice mine that can be left in place to rapidly degrade into a non-obtrusive natural substance would eliminate the time and expense of recovering practice mines. Until now, such a useful, degradable, practice mine has not been available.
The assignee of the present invention previously experimented with a mine fabricated from peat to fill the need for a degradable mine, but did not further pursue this type of mine by patenting or marketing because it did not meet the overall requirements. The unsuccessful peat mine was lower in weight than a tactical mine and had a tendency to break up during launching and/or landing.
The present invention overcomes the drawbacks of currently available practice mines by, for the first time, providing a degradable practice sand mine that requires no extra effort to recover once it has been launched from a scatterable mine system. At the same time, a degradable practice mine contemplated by the present invention nearly matches the weight of a tactical mine and has characteristics that allow it to survive launching from a mine launching tube and landing while maintaining its shape. The invention takes advantage of the fact that sand is a very unobtrusive substance that is not likely to cause any environmental damage in the areas where training is taking place.
A method for making a degradable practice mine including the steps of covering a flat work surface with a polyethylene sheet to serve as a release film, weighing out the materials, mixing polyvinyl alcohol (PVA) with sand making a sand/PVA mixture, filling a mold with the sand/PVA mixture, consolidating the sand/PVA mixture to make a consolidated form in the shape of a mine, and heating the consolidated form to make a hardened mine form mimicking the shape and launching characteristics of a tactical mine.
In one aspect the invention provides a degradable practice mine that nearly matches the weight of a tactical mine, and that can survive launching from an air gun mine launching tube, and subsequently landing while maintaining its shape.
In another aspect of the invention a degradable practice mine is comprised of sand, since sand is a very unobtrusive substance that is not likely to cause any significant environmental damage in the areas where training is taking place.
An advantage of the invention is that it provides a degradable practice mine comprising natural substances that degrade rapidly when exposed to sunlight and water.
In another aspect the invention provides a degradable practice mine that can be painted to meet color-coding requirements, and coated with paraffin wax to improve handling and storage.
In another aspect the invention provides a degradable practice mine designed to have nearly the same weight as the tactical mine that is used in scatterable mine systems, thereby having launch and flight characteristics nearly matching characteristics of the tactical mine.
In another aspect the invention provides a degradable practice mine having few complex features to allow for simple molding.
It is one object of the invention to provide a degradable practice mine for field trials and training that does not require retrieval from the field in order to prevent harm to the environment.